Backing-off tool for taps.



A. NYARY.

BACKING oFFwooL 'FOR TAPS..

APPLICATION FiLED MAR. 22. l9l6.

1,284,431 Patented Nov. 12, 1918.

ZG'Q .Z /6

ANTHONY NYARY, 0F ST. LOUIS, MISSOURI.

BACKING-OFF TOOL FOR TAPS.

C Specification of Letters Patent.

Patented Nov. 12, 1918.

Application filed March 22,' 1916. Serial No. 85,885.

To all whom t may concern:

Be it known that I, ANTHONY NYARY, a subject of the Emperor 0f Hungary, and a resident of the city of St. Louis and State of Missouri, have invented certain new and useful Improvements in Backing-Off Tools for Taps, of which the following is a specification.

The primary object of this inven-tion is to provide a backing-oit or clearance providing tool for specially constructed taps which can be attached to a lathe.

Another object is to provide a toolthat is automatic in its operation in which the tool is adapted to intermittently engage and disengage the tap at the points or places where clearance is to be given to the threads of the tap.

A further object is to provide an improved reciprocally mounted tool for the construction of special taps, that is adapted to Ibe operated by the tool as the tap is rotated.

Other and further objects will appear in the specification, and be specifically pointed out in' the appended claims, reference being had to the accompanying drawings exemplifying the invention, and in which,

Figure l is a longitudinal vertical section l taken through this improved tool.

Fig. 2 is a plan view of Fig'. 1.

Fig. 3 is a transverse vertical section taken on the line 111-111 of Fig. 2.

Referring to the drawings: 1 designates a body portion which is recessed as shown at 2, and extending from said body portion 1 is a shank 3. Reciprocally mounted in the recess 2 is a tool holder 4, said tool holder being slidably mounted at one end yon the top surface 5 of the shank 3, and the opposite end of said tool holder being slidably mounted on the transverse portion 6 of the body portion 1.

Pivotally mounted on the aXis 7 and in the recess 2 is an lfshaped lever 8, and formed on the vertical portion of said lever adjacent the aXis 7 thereof is a cam surface 9.

Formed in the forward end of the tool holder 4 is a cuttingtool retaining socket 10,-and mounted in said socket is a cutting tool 11, saidy tool being securely heldin position by .the set screw 12. Formed in the tool holder 4, rearwardly of the socket 10 is a vertically. arranged threaded opening 13, and-mounted in said opening and in en- "gagement with the threads thereof is an adjusting screw 14, the lower endof said screw being tapered as indicated at 15, said screw having the operating handle 16. Formed in said holder 4 adjacent the lower end of the vertical opening 13 is a horizontally arranged bore 17, and slidably mounted in said bore is a wedge pin 18, one end of said pin being tapered as indicated at 19, said tapered end 19 being adapted to abut the tapered end 15 of the adjusting screw 14, the opposite end of said wedge pin 18 being in engagement with the cam surface 9 of the L-shaped lever8. A spring seat 20 is formed in said holder 4, said spring seat being for the reception of a horizontally arranged coil spring 21, the outer end of said spring being adapted to abut the transverse portion 6 of the body portion 1.

Formed in the horizontal portion 22 of `the L-shaped lever 8 are a pair of guide-y ways 23, said guide-ways being for the reception of a main adjusting block 24. Formed in the end piece 25 of the lever 8 is a horizontally arranged threaded opening 26, and mounted in said opening is an adjusting screw 27, said screw having one end secured to the adjusting block 24 by the pin 28. Formed in the block 24 is a horizontally arranged dove-tailed guiding groove 29, and slidably mounted in said groove is an auxiliaryblock 30, said block 30 being for the support of a vertically arranged threaded post 31, said post being supported by the adjusting nut 32 which is mounted in the opening 33, said opening being formed in said block 30.

Longitudinally formed in said post 31 is a keyway 34, said keyway being for the reception of a key 35 that is carried by the block 30. Turnably mounted at the upper end of said post 31 is a guiding roller 36. EXtendj ing upwardly from said block 24 is an ear 37, said ear having a horizontally threaded opening 38 formed therein, said opening be ing for the reception of an adjusting screw 39, one end of said screw being secured to the block 30 by the pin 40. A recess 41 is formed in the block 24 adjacent the threaded post 31, said recess being for the purpose of allowing said post to travel horizontally in said block 24.

Mounted on the lower end of the post 31 This improved tool is designed for the purpose of properly backing-oftr1 or providing clearance to specially constructed taps in which it is essential to reduce the rear portions of the cutting threads so that the size of the threads at the rear will be smaller than the forward part, or real cutting edges of the tap threads.

The operation of this improved device is as follows: The tap A which is to be backed o is properly centered in the chuck of the lathe, not shown, and the shank 3 of this improved device is secured in the ordinary lathe tool head B. The adjusting block 24 is then centrally arranged beneath the tap b y the adjusting screw 27, and after the cutting edge 11 has been mounted in the tool holder 4 and secured thereto by the set screw 12, the adjusting block 30 is manipulated by the adjusting screw 39 until the roller 36, which is carried by the threaded post 81 is brought to a proper position as regards its engagement with the threads of the tap, which position is in the root of a thread, which is one ahead of the root of the thread which the point of the cutting edge 11 will occupy. If it is found that the roller 36 does not contact properly with the tap, proper adjustment can be provided by manipulating the adjusting nut 32.

From the aforesaid arrangement it is to be seen that when the tap is turned in the Vdirection indicated by the arrow, the cutting threads of the tap will be turned toward the cutting edge 11, and as the roller 86 is forced out of each flute C of the tap prior to said roller engaging between a pair of threads, the horizontal portion 22 of the lever 8 will be forced downwardly, thereby causing the cam surface 9 of said lever to bear against thewedge pin 18, and inasmuch as said pin is wedged against the adjusting screw 14, the tool holder a will be moved forwardly so that the point of the cutting edge 11 will be engaged between a pair of the tap threads.

As the cutting tool is moved forwardly the point thereof will enter between the threads and will engage each adjacent pair of threads approximately along the path as indicated by the dotted line-D of the tap thread E so that the cutting edge will engage the root of the thread adjacent the rear end of the cutting threads. As soon as the cutting edge has emerged forwardly from a pair of threads, it is essential that the same be immediately withdrawn, so that said cutting edge 11 will not engage the front orcutting edge of thei tap threads as indicated-at l?. This retracting movement of the cutting edge 11 is broughtabout as the roller 36 rides out from between a pair of threads, and into an adjacent flute C, in which the cam face 9 of the lever 8 will be moved toward its former position, thereby allowing the coil spring 21 to force the-"tool holder'l rearwardly to its normal position. It is therefore seen that as the tap A is continually revolved, reciprocation will be given to the tool holder l and cutting edge 11 as the horizontal portion 22 of the lever 8 is forced downwardly by the rotation of the tap, and is moved upwardly through the agency of the spring or springs 113.

In inserting the cutting edge 11 of the tool holder into its retaining socket and securing it thereto by the set screw 12, it is of course necessary to use some j-udgment as to the distance which said cutting edge should protrude from the socket, but in order to provide a microscopic adjustment to said cutting edge after the same has been clamped to the tool holder, the adjusting screw 14, when manipulated will cause the tool holder to be moved forwardly or rearwardly as desired on account of the tapered end 15 of said adjusting screw being adapted to bear and wedge against the tapered end 19 of the wedge pin 18, said wedge pin at all vtimes bearing against the cam surface 9 of the lever 8.

From the aforesaid description it is to be readily seen that when an improved tool'of this character has been placed in proper working position relative to a revolving tap, that an. improved automatic backing-0E tool has been provided.

What 1 claim is:

1. A clearance providing tool for cutters7 comprising a reciprocally mounted holder,y

a cutting tool secured to said holder, said cutting tool being coperable with a revolubly mounted cutter, and means connected to said holder in engagement with said cutter for reciprocating said holder.

2. A clearance providing tool for cutters and the like comprising a reciprocally mounted holder, a cutting tool carried by said holder for engagement with a revolubly mounted cutter, and a lever in engagement at one end with said holder, and at its opposite end adapted to cooperate with saidA cutter for reciprocating said` holder.

8. 1n a backing-off tool for cutters and the like, thecombination of a body portion, a tool holder 'bearing a cutting tool reciprocally mounted on said body portion, a pivoted lever having one of its ends engaging said holder, said lever at its opposite end adapted to bear against the article being backed off, and to be actuated thereby as the article is revolved.

a. A backing-o device for revolubly mounted tools comprising a movably mounted holder, a cutting edge carried by said holder, and means for moving said holder in engagement therewith, said means also being adapted to engage the revolving tool being worked upon, thereby providing movement to said holder.-

5. The combination of a reciprocally mounted tool holder bearing a cutting edge, and a member providing means for reciproeating said holder, said cutting edge adapted to engage and disengage between the threads of a revolubly mounted tap, said member adapted to be depressed by the revolving tap, thereby reciprocating said holder.

6. A clearance providing device for operating on a cutting element, said device comprising a reciprocally mounted tool holder, an oscillatably mounted member for engagement with said holder and adapted to engage the cutting element being operated on, and an adjusting member located between said holder and said oscillating member.

7. A backing off tool for cutters and the like comprising a reciprocally mounted tool holder, a lever operably related to said holder adapted to reciprocate lsaid holder, and a follower carried by said lever adapted to engage the threads of a cutter when said cutter is mounted above said follower, said cutter when revolved adapted to actuate said lever.

8. The .combination of a cutting tool, and operating means coperable therewith, said means adapted to cooperate with the article being worked upon by said cutting tool, whereby, when the article is revolved, said tool is reciprocated.

9. A backing oif tool for cutters and the like comprising a body portion, a tool holder adapted to bear a cutting tool reciprocally mounted in said body portion, a cam for engagement with saidv holder, adapted to be actuated byv a cutter being worked upon by the cutting tool of said holder, said cam causing said holder to reciprocate, and an adjusting element for adjusting said holder relative to said cam.

l0. A clearance providing tool for taps and the like, comprising a reciprocally mounted tool holder, a lever operably re lated to said holder adapted to reciprocate said holder, a follower carried by said lever adapted to engage the threads of a tap, when the tap is mounted above said follower so that the revolving 4of the tap will actuate said lever, and adjusting means carried by said lever for adjusting said follower.

11. In a device for backing off cutters and the like, the combination of a cutting tool holder bearing a cutting tool adapted to cooperate with a revolubly mounted cutter being backed ofi', means for reciprocating said holder adapted to engage the cutter so that the cutting tool carried thereby will engage and disengage the cutter during the revolving thereof, and means provided whereby the cutter being backed oft1 serves as its own templet relative tothe cutting tool properly engaging the cutter.

12. In a backing-off tool, a movable body portion bearing a cutting edge, a lever for moving said body portion, adjusting means related to said lever and said body portion, said lever adapted to coperate with the article being backed-off, and means for adjusting said lever relative to the article.

13. In a backing off tool, a movable body portion bearing a cutting edge, a lever for moving said body portion, a wedging ele- .ment related to said lever and said body portion, and an adjustable follower carried by said lever for cooperation with the article being backed off.

14. In a backing-off tool, a body portion bearing a cutting edge, and a lever for operating said body portion, in which the article being backed off is adapted to rock said lever, thereby operating said body portion.

ANTHONY NYARY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

